Spring-winding mechanism.



-0. OHLSON.

SPRING WINDING MECHANISM. APPLICATION FILED JAN. 9, 19Q6.

PATENTED NOV. is, 1906.

UNITED STATES PATENT OFFICE.

()LOF OHLSON, OF NEINTON, MASSACHUSETTS, ASSIGNOR TO AMERICAN WALTHAM WATCH COMPANY, OF WALTHAM, MASSACHUSETTS, A COR- SPRING-WINDING MECHANISM.

Specification of Letters Patent.

Patented Nov. 13, 1906.

Application filed January 9, 1906. Serial No. 295.236.

To a, whom it may concern:

Be it known that I, OLOF OHLSON, of Newton, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Spring-VVinding Mechanisms, of which the following is a specification.

This invention relates to watches or clocks, and particularly to the mainspring-winding mechanisms thereof. Its object is to provide an improved form of recoiling click or pawl for engaging the winding-wheel of the watch or clock movement to prevent unwinding of the spring.

In particular the invention is designed to produce a click which will prevent the mainspring ever becoming wound too tight and will be so constructed as to be retained always in correct engagement with the windingwheel without the necessity of an external spring.

The preferred embodiment of my invention is hereinafter fully described and claimed and is illustrated in the accompanying drawings, in which I Figures 1 and 2 represent fragmentary plan views of a watch or clock, showing the winding-wheel and click in two positions. Fig. 3 represents a perspective view of the click. Fig. 4 represents a sectional view on line 41 4 of Fig. 1.

The same reference characters indicate the same parts in all the figures.

Referring to the drawings, 10 represents the usual winding-wheel of a watch or clock movement, which is secured to the arbor of the mainspring-drum and which is provided with a series of gear-teeth 11 to be engaged by the winding mechanism and also by a click or pawl to prevent unwinding.

12 represents the top or cover plate of the timepiece, which is shaped so as partly to surround the winding-wheel and to extend over other parts of the movement. The top plate has a recess 13, in which is placed the click or pawl 14. The click surrounds a tubular stud 14 integral with the plate about which it is free to turn pivotally and is retained by a screw 15. Projecting from one side of the click there is an arm 16, which has a lateral toe or looking projection 17, which is adapted to enter the space between two adjacent teeth of the winding-wheel and the Y wheel.

end surface 18 of which is adapted to bear against a tooth and prevent movement of the winding-wheel in the direction of the arrow in Fig. 1, this being the direction in which the mainspring under tension tends to move the The arm 16 extends from the pivot of the pawl in the direction approximately tangential to the winding-wheel, and the end face 18 is approximately radial to the winding-wheel when the locking-toe is engaged with tooth of the wheel. Thus the pressure of the mainspring is applied in a line nearly perpendicular to the face 18 and transmitted directly along the arm 16 to the pivotscrew 15, producing a direct thrust with substantially no twisting tendency.

The click is provided with a second proj ection 19, which is adapted to enter a space between two of the winding-wheel teeth and is separated from the locking projection 17 by a space equal to two or more times the pitch of the teeth 11. The tooth 19 extends away from the center of the pawl in a substantially radial direction and is formed upon the end of a thin strip 20, which is of hooplike form and encircles the pivot of the click, being wholly separated from the click except at the point 21, where it joins one side of the arm 16. The click is made of elastic metal, preferably of steel, so that the curved strip 20 is resilient by reason of the large ratio between its length and cross-section. Thereby the tooth 19 is resiliently mounted and yields radially toward the center of the pawl. When the mainspring is being wound up, the winding-wheel 10 is turned in the direction of the arrow on Fig.2, and thereby the tooth 19, being engaged by a tooth 11, causes the click to swing about its pivot in lefthand rotation, carrying the locking-toe away from the wheel until it brings up against the wall 22 of the recess, which forms a fixed stopshoulder and arrests the toe of the click, limiting its movement away from the wheel. The distance between the shoulder and wheel is less than the normal distance between the outer corner of the arm 16 and the end of tooth 19, and thus when this part of the arm strikes the shoulder the end of the tooth will project somewhat into one of the spaces of the winding-wheel and will be forced backwardly against the yielding pressure of the strip 20 every time one of the teeth 11 passes.

As soon as the winding-pressure is removed from the wheel the latter turns back in the direction indicated in Fig. 1 by the arrow, tooth 19 slipping into one of the notches of the wheel and being returned into normal position, thereby carrying toe 17 into one of the spaces and into engagement with one of the teeth 11. There is not sufficient resist ance to the movement of the click to cause the resilient strip 20 to be distorted, so the distance between the projections 17 and 19 is not increased above the normal amount when the click is being returned. As this distance is equal to a whole number of the tooth-spaces, the locking projection is moved directly into correct engagement with the winding-wheel without possibility of striking upon the end of one of the teeth 11.

Preferably the click is made as an integral whole from a single piece and has a central portion or eye 23, provided with a hole 24 for the reception 01 a pivot. The circular hoop 20 is concentric with the central portion and its hole 24. In making the click preferably the blank is bored partially through to form a recess nearly as large in diameter as the circular part of the click. Then the partially-formed blank is milled. around its periphery on the other side to remove the stock between the central portion 23 and hoop 20, thereby separating the latter from the body of the pawl at all points except the portion 21, where it is joined to the toe. The portion of the stock between the tooth 19 and the projection 25 is then removed to leave the tooth free.

It will be seen that with a click constructed as above described its own resilience causes it to remain in engagement with the winding-wheel, and there is thus no necessity for providing a separate spring for that purpose, the only necessity being to provide a stop or abutment to prevent the click moving so far as to allow the teeth 19 to separate from the winding wheel. The teeth 19 causes the locking-toe of the click to be separated from the winding-wheel when the mainspring is wound up tight. and allows the latter to unwind by a slight amount before the locking projection can come into engagement with the wheel and hold it. Thus it is impossible even when the spring is completely wound for the convolutions to be wrapped tightly enough about each other to bind.

I claim- 1. In a 1nainspring-winding mechanism, the combination with a toothed windingwheel, of a click having a locking projection and a tooth resiliently mounted on the click for engagement with the winding wheel teeth.

2. In a mainspringavinding mechanism, the combination with a toothed windingwheel of a click having a locking projection and a tooth for engagement with the wheelteeth adapted to turn the locking projection a distance greater than thepitch of the wheel teeth, said click-tooth being resilient, and a fixed. stop arranged to arrest the click with its tooth in contact with the wheel.

3. In a mainspring-winding mechanism, the combination with a plate having a shoulder, and a toothed winding-wheel, of a click pivoted to the plate and having a locking projection adapted to engage the wheel, the click having also a resilient tooth for engagement with the wheel-teeth to turn the locking projection, and the shoulder being arranged. to retain the click with its resilient tooth in engagement with the wheel-teeth.

4. In a mainspring-winding mechanism, the combination with a toothed windingwheel, of a click or pawl having a locking-toe and an integral tooth resiliently joined to the pawl, said tooth being arranged lor engagement with the wheel-teeth to move the locking-toe toward and from the wheel.

5. A click or pawl having a rigid too or locking projection and a yielding, resilient projection or teeth.

6. In a spring-winding mechanism, a recoiling click for engagement with the winding-wheel having a locking projection or toe and an integral, resilient strip provided with a lateral projection.

7. A click or pawl for spring-winding mechanisms having a locking projection or toe, a circular, resilient strip, and. a projection l'ormed on the end ol said strip.

8. A click or pawl having a locking projed tion or tee, a circular resilient strip integrally termed therewith, and a tooth formed on the strip extending radially thereof.

9. A click having a portion adapted to be pivotally mounted, a locking projection or toe, and a resilient strip or hoop curved cir cularly about the pivotal center and provided with an outwardly-extending tooth projection on its end.

10. In a inainspring-winding mechanism, the combination with a toothed windingwheel, 0'[ a click pivoted adjacent the wheel, and comprising a circular portion through the center of which the pivot extends, an extension irom the circular portion terminatin in a lateral projection lor engagement with the wheel-teeth, and a tooth extending fromv the circular portion and cooperating with the wheel-teeth, the tooth and greater part ol" the circular portion being separated from the body of the click and being made ol spring material.

In testimony whereof I have a'lllxed my signature in presence of two witnesses.

OLOF ()IILSON.

I/Vitnesses HELEN A. MosnEn, E. A. MAnsn. 

